Chair base



April 22, 1969 KQN. PAQUETTE CHAIR BASE Filed Nov. 16, 1966 ,W/JW Z Z7 8f i 4 W 5 Unlted States Patent 3,439,893 CHAIR BASE Kenneth N. Paquette,Muskegon, Mich., assignor to The Shaw-Walker Company, Muskegon, Mich., acorporation of Michigan Filed Nov. 16, 1966, Ser. No. 594,782 Int. Cl.F16m 11/00, 13/00 U.S. Cl. 248405 1 Claim ABSTRACT OF THE DISCLOSURE Aswivel chair base having a locking arrangement which permits assemblyand disassembly and wherein the height of the chair is adjusted bymanipulating a cylindrical sleeve which presents no outside irregularityand wherein a spring latch under ordinary circumstances holds the chairand base against vertical displacement while permitting free angularrotation.

Summary 07 the invention A base for a swivel chair seat, including asleeve terminating at its upper end in an upwardly open, outwardlyflared conical female bearing pocket, adapted to receive a conical malethrust bearing ring, a seat supporting screw slidably centered in thering, a nut threaded on the screw, adapted to rest on the ring, anadjusting tube rigid on the nut adapted to enclose the bearing pocket, alatch spring fixed and enclosed in the tube projecting in wardly fromthe wall thereof, beyond the outer periphery of the pocket whereby upondownward assembly movement of the tube, screw and nut toward the pocket,the spring latch is compressed to permit seating of the nut on thebearing and as a result being below the pocket, yield ingly resistsupward withdrawal of the nut, screw and tube.

Other objects will appear from time to time throughout the specificationand claims.

The invention is illustrated more or less diagrammatically in theaccompanying drawings, wherein FIGURE 1 is a side elevation in partsection of the seat portion and the base in assembled working position;

FIGURE 2 is a detail elevation in part section on an enlarged scaleshowing the chair iron and base as they are about to be assembled;

FIGURE 3 is a similar elevation in part section showing the position ofthe parts as assembly continues;

FIGURE 4 is a plan view of the latch mechanism.

Like parts are indicated by like numerals throughout specification anddrawings.

The chair iron 1 is the framework upon which the conventional type ofseat adjustment is mounted for angu lar adjustment. The verticaldownwardly depending adjusting screw 2 is rigidly attached to the chairiron 1 by the clamp 3. The cover tube 4 carried by the chair iron 1extends downwardly therefrom and encircles the screw 2. An adjusting nut5 threaded on the screw 2 carries the downwardly depending adjusting ornut rotating tube 6 which may telescope within the cover tube 4.

The nut 5 is radially grooved at 7 on its lower face to interlock withradial ridges 8 on the upper face of the annular, conical, male, nylon,thrust bearing ring 9. The screw 2 extends downwardly through the ring 9into the base sleeve 10 which is conically flared at its upper end at 11to define an upwardly disposed, female, bearing surface to receive thering 9.

The base sleeve 10 is permanently mounted at its lower end on the basearms 12 so that with the parts in the position shown in FIGURE 1, theoperator may rotate the adjusting tube 6 to rotate nut 5 to raise orlower it and the chair seat. The nylon ring 9 interlocking with the nut5 is free to rotate in the female bearing surface 11 when the adjustmentis made. In use, the chair seat may be turned in the usual manner.Turning the seat carries with it the screw, cover tube nut, adjustingtube and the bearing ring which all rotate in unison unless theadjusting tube is held manually against rotation.

The above description of the chair is necessary to provide a backgroundfor the particular invention here involved, namely-the hidden latchwhich makes it possible to assemble and disassemble the seat and baseand which holds them together except when purposely disassembled.

The hidden latch includes a spring anchor 13 welded or otherwiseattached at its ends to the inner wall of the adjusting sleeve 6 betweenits ends and spaced from the nut sleeve at 14 to form a pocket closed atthe bottom by a lug 15 and recessed at 16. The pocket receives the lowerend of a latch spring 17. A lug 18 pressed outwardly from the springpenetrates the recess 16. The latch spring is thus held in the positionof FIGURE 2 with the central outwardly bowed portion thereof extendinginwardly from the wall of the sleeve '5 a distance greater than theclearance between the flared end of the tube 10 and the sleeve wall.

As the seat and base portion of the chair are about to be assembled, thescrew with the nut in the uppermost position are aligned with the basesleeve 10 and lowered into the position shown in FIGURE 2 with the latchspring extending inwardly above the thrust bearing 9 and the flared end11. Further movement such as shown in FIG- URE 3 compresses the springbetween the wall of the adjusting or nut tube and the flared end of thesleeve 10. Further movement brings the parts into the position shown inFIGURE 1 where the not 5 and the male bearing 8 interlock with the latchspring now below instead of above the flared support sleeve end.Downward movement of the latch spring is limited by contact of the endof the spring with the lug 15.

The strength of the latch spring and there might be, if desired, morethan one is such that when the chair is lifted by holding on to theseat, the base comes along. Upward movement of the spring under thosecircumstances is prevented by penetration of the lug 18 into the recess16, but if it is necessary to separate the base from the seat, all thatis needed is to hold the base down, give a powerful jerk upwardly to theseat when the spring will be overcome in reverse direction and the partswill be separated.

The cover tube 4, the adjusting tube 6 and the fixed inner tube 19 onthe base define a smooth walled cylindrical column like tubular shieldto mask all the adjusting and working parts below the chair iron, thuslending themselves to a satisfactory stream-line design with the latchentirely masked.

I claim:

1. A vertically adjustable swivel chair, including a base, a seatassembly, a vertical screw permanently attached to the seat assembly, abase sleeve extending upwardly from the base, flared at its upper end todefine an upwardly disposed, conical, female, thrust bearing surface, anannular, downwardly disposed, conical, male, thrust bearing ring,encircling the screw, adapted to penetrate the female bearing surface, anut threaded on the screw, resting upon the bearing ring, an adjustingsleeve extending downwardly from the nut, latch means within theadjusting sleeve to yieldingly resist upward movement of the nut fromthe thrust bearing ring, said means including a latch leaf springvertically disposed on the adjusting sleeve and extending inwardly fromthe inner Wall of the adjusting sleeve a distance greater than theclearance between the adjusting sleeve and the flared support sleeve,the lower end of the spring being socketed in a spring anchor on theinner wall of the adjusting sleeve which permits expansion andcontraction of the sleeve but inhibits vertical longitudinaldisplacement thereof.

4 References Cited UNITED STATES PATENTS 3,059,888 10/1962 Lie 248-1612,405,013 7/1946 Campbell 248408 2,999,665 9/1961 Ericson et al. 248-4053,164,357 1/1965 Hage et a1. 248406 FOREIGN PATENTS 1,045,510 10/1966Great Britain.

FRANCIS K. ZUGEL, Primary Examiner.

US. Cl. X.R. 248-159

